CWI NDE Methods and Symbols 2

Question 1

Which NDE symbol on a weld drawing indicates that liquid penetrant testing should be performed?

Accepted Answer

PT

Answer

PT is the AWS standard abbreviation for liquid penetrant testing used in NDE symbols on weld drawings.

Question 2

In ultrasonic testing, what does the term 'dead zone' refer to?

Accepted Answer

The region near the transducer face where defects cannot be detected

Answer

The dead zone is the area directly beneath the transducer where ringing from the initial pulse masks any near-surface reflections.

Question 3

Which type of radiographic film has the finest grain size and highest resolution but requires longer exposure times?

Accepted Answer

Class I (fine grain)

Answer

Class I fine-grain films produce the highest resolution images but require longer exposures because they are less sensitive to radiation.

Question 4

When performing magnetic particle testing, what is the purpose of the 'residual method'?

Accepted Answer

Testing is done after the magnetizing force is removed, relying on retained magnetism

Answer

The residual method applies particles after removing the magnetizing force, and works only on materials with sufficient residual magnetism (high retentivity).

Question 5

In liquid penetrant testing, what is the correct sequence of steps?

Accepted Answer

Precleaning → Penetrant application → Dwell time → Excess removal → Developer → Inspection

Answer

The correct LP sequence is precleaning, penetrant application, dwell time, removal of excess penetrant, developer application, then inspection.

CWI Practice Test

CWI Practice Test

CWI NDE Methods and Symbols 2